In general, widely used as a coating film transfer tool is an automatically winding type coating film transfer tool in which a paying-out core having a coating film transfer tape wound thereon and a rewinding core that rewinds the coating film transfer tape after use are interlocked via a power transmission mechanism in a case, and a rotational torque of the rewinding core or the paying-out core is generated by a frictional force generating on a sliding surface between components by using a restoring force of a resilient body. Publicly known specific examples of a mode using a restoring force of a resilient body include configurations using resiliency of a resin as described in PTL 1, resiliency of an O-ring as described in PTL 2, and resiliency of a compression spring as described in PTL 3.
Among these configurations, the ones using resiliency of a resin or an O-ring are affected by creep, and thus have difficulty in adjustment of a rotational torque. The ones using resiliency of a compression spring, being less affected by creep and achieving a load stable for a long time, are easy to adjust.
FIG. 11 to FIG. 13 illustrate a mode of a general coating film transfer tool of the related art in which resiliency of a compression spring is used.
FIG. 11 is a front view of a coating film transfer tool 100. FIG. 12 is an enlarged vertical cross-sectional view taken along the line XII-XII in FIG. 11. FIG. 13 is an exploded perspective view of a principal portion in FIG. 12 which is reduced in scale. Two members of a compression spring 104 and a paying-out core gear 105 are fitted in sequence on a resilient locking piece 102 of a rewinding button 103, which has a locking portion 101 at an end thereof. The resilient locking piece 102 of the rewinding button 103 is rotatably fitted on a support shaft 107 projecting inward of a case 106. The rewinding button 103 and a paying-out core 108 are configured to rotate integrally with each other. In this configuration, frictional forces generating on a sliding surface (dotted circle X) between the compression spring 104 and the rewinding button 103, a sliding surface (dotted circle Y) between the compression spring 104 and the paying-out core gear 105, a sliding surface (dotted circle Z1) between the paying-out core gear 105 and the paying-out core 108, and a sliding surface (dotted circle Z2) between the locking portion 101 of the rewinding button 103 and the paying-out core gear 105 generate a rotational torque of the rewinding core via a power transmission mechanism.
In contrast, with generally available compression springs, it is difficult to manage a surface condition of the wire. Therefore, since the coil wires to be used have different surface states, friction generated with respect to mating members varies. This leads to a problem of high variability in generated rotational torque.
In addition, it is not constant whether the compression spring slides on a rewinding button or with a paying-out core gear, and the portion of the compression spring which slides on these members is also not always the same, so that variability may result. If the variability in rotational torque is high, the rotational torque needs to be set to a relatively high value, to wind a coating film transfer tape even at the lowest expected rotational torque. However, if the rotational torque is excessively high, usability is worsened because a larger force is required for transfer and, in addition. The surface of the compression spring may also cause earlier wearing of the mating member. Consequently, there is a problem that the rotational torque changes between the initial use and final use.